the car wash can be expensive, doing it yourself takes extra care. here to show us how, the dos and don'ts is jake fisher, senior automotive engineer for the consumer reports test center. good morning, great to have you here. >> good morning. >> i take my car in after it snows. however should we really wash our cars? >> if you're worried about your car the best advice do it once a week. even in snow it's like sure, you know, the car like this turns white, you know with all the salt. >> looks bad. >> and corrosive. but even in spring there's the tree sap, bird droppings, all that stuff could go and really damage your paint. so once a week you could really keep that car clean. >> i always wonder, do you need to buy this special car wash or can you use any soap? >> actually, you do need to get the special car wash. because what -- if you get the dish washing stuff, look at what's on a dish, the dish, you know, it's not painted, not waxed. you take your car and put it in the dishwasher it's corrosive to the paint and wax. get a nice car wash.